1. Field of the Invention
The present general inventive concept relates to an electrophotographic image forming device, and more particularly, to an electrophotographic image forming device having a fusing unit, which is safely detachably mounted therein.
2. Description of the Related Art
Generally, an electrophotographic image forming device comprises a paper supplying unit, an image forming unit, a fusing unit, and a paper discharging unit. As the paper supplying unit supplies a paper to the image forming unit, the image forming unit selectively applies a developer to the paper using a potential difference, thereby forming a developer image thereon. The fusing unit fixes the developer to the paper to set the developer image. The paper discharging unit receives the paper with the developer fixed thereon from the fusing unit and discharges the paper outside the electrophotographic image forming device.
The fusing unit comprises a couple of fusing rollers that rotate opposite to one another through which the paper is transferred for applying heat and pressure thereto. As the fusing rollers having a heating apparatus perform a fusing operation, a high temperature is produced. The developer that is applied to the paper is fixed thereto by the fusing rollers that apply the heat and pressure. However, when the fusing unit operates abnormally, which may be caused by expiration of its lifespan, the developer may be fixed on the paper without stability and may be exfoliated therefrom.
When the lifespan of the fusing unit expires, the fusing unit is removed from a main body of the electrophotographic image forming device and is replaced. The lifespan of the fusing unit is typically shorter than a life span of the electrophotographic image forming device. In particular, as the life span of the electrophotographic image forming device increases (as it has in relatively recent years), the fusing unit becomes expendable. Moreover, it becomes necessary for the fusing unit to be detachable from the main body of the electrophotographic image forming device in case that a paper gets jammed, a malfunction occurs in the fusing unit or surrounding components, or the lifespan of the fusing unit expires. Furthermore, it is important that the fusing unit be detachably mounted thereon safely and conveniently.
FIG. 1 is a perspective view schematically illustrating a conventional electrophotographic image forming device. As illustrated in FIG. 1, the conventional electrophotographic image forming device includes a fusing unit 2 mounted in a housing 1. The fusing unit 2 can be detached from housing 1 when the lifespan of the fusing unit 2 expires, or when the fusing unit 2 or the conventional electrophotographic image forming device needs to be repaired. A user can typically remove some parts of the housing 1, disassemble a coupling member (not shown) that couples the fusing unit 2 to the housing 1, and then detach the fusing unit 2 along a paper transfer direction (direction A), which is perpendicular to a rotational axis of a fusing roller 3 of the fusing unit 2.
However, the conventional electrophotographic image forming device has the following problems.
First, when the user holds the fusing unit 2 when detaching it from the housing 1, the user may come into contact with the fusing roller 3, which may be very hot, thereby possibly getting burned. Since an entire length of the fusing roller 3 is exposed to the user when the fusing unit 2 is detached from the housing 1, it is easy for the user to accidentally contact the fusing roller 3 and get burned.
Second, there is a need for the coupling member (e.g., a screw) to attach the fusing unit 2 to the housing 1. The coupling member should be able to withstand a resistance produced by the paper being transferred and a centrifugal force of the fusing roller 3, because a detachment direction of the fusing unit 2 is the same as that of a rotation direction of the fusing roller 3 and the paper transfer direction. Thus, in order to mount/detach the fusing unit 2 in/from the housing 1, the user is required to assemble or disassemble the coupling member of the housing 1. This can be difficult and inconvenient for the user. Further, the coupling member may get lost when it is disassembled from the housing 1 and the fusing unit 2 is detached.
Third, the fusing unit 2 is typically located in a back of the housing 1 according to the conventional electrophotographic image forming device. Thus, the fusing unit 2 is mounted/detached in the back of the housing 1 resulting in poor accessibility. Additionally, since the conventional electrophotographic image forming device is typically arranged so that the back thereof faces a wall, the user is required to move the conventional electrophotographic image forming device in order to mount or detach the fusing unit 2. This also causes the user an inconvenience and may be difficult, especially when the conventional electrophotographic image forming device is large